WO2015125594A1 - キャパシタおよびその充放電方法 - Google Patents
キャパシタおよびその充放電方法 Download PDFInfo
- Publication number
- WO2015125594A1 WO2015125594A1 PCT/JP2015/052812 JP2015052812W WO2015125594A1 WO 2015125594 A1 WO2015125594 A1 WO 2015125594A1 JP 2015052812 W JP2015052812 W JP 2015052812W WO 2015125594 A1 WO2015125594 A1 WO 2015125594A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- positive electrode
- capacitor
- activated carbon
- active material
- negative electrode
- Prior art date
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
- H01G11/04—Hybrid capacitors
- H01G11/06—Hybrid capacitors with one of the electrodes allowing ions to be reversibly doped thereinto, e.g. lithium ion capacitors [LIC]
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- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
- H01G11/14—Arrangements or processes for adjusting or protecting hybrid or EDL capacitors
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- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
- H01G11/22—Electrodes
- H01G11/24—Electrodes characterised by structural features of the materials making up or comprised in the electrodes, e.g. form, surface area or porosity; characterised by the structural features of powders or particles used therefor
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- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
- H01G11/22—Electrodes
- H01G11/26—Electrodes characterised by their structure, e.g. multi-layered, porosity or surface features
- H01G11/28—Electrodes characterised by their structure, e.g. multi-layered, porosity or surface features arranged or disposed on a current collector; Layers or phases between electrodes and current collectors, e.g. adhesives
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- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
- H01G11/22—Electrodes
- H01G11/30—Electrodes characterised by their material
- H01G11/32—Carbon-based
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- H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
- H01G11/22—Electrodes
- H01G11/30—Electrodes characterised by their material
- H01G11/32—Carbon-based
- H01G11/34—Carbon-based characterised by carbonisation or activation of carbon
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- H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
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- H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
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- H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
- H01G11/66—Current collectors
- H01G11/72—Current collectors specially adapted for integration in multiple or stacked hybrid or EDL capacitors
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- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
- H01G11/84—Processes for the manufacture of hybrid or EDL capacitors, or components thereof
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- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/34—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering
- H02J7/345—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering using capacitors as storage or buffering devices
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/13—Energy storage using capacitors
Definitions
- the present invention relates to a capacitor charged and discharged at a high charge upper limit voltage and a method for charging and discharging the same.
- ⁇ Amid the close-up of environmental issues, systems that convert clean energy such as solar or wind power into electric power and store it as electric energy are being actively developed.
- a lithium ion secondary battery As such an electricity storage device, a lithium ion secondary battery, an electric double-layer capacitor (EDLC), a lithium ion capacitor, and the like are known.
- capacitors such as EDLCs and lithium ion capacitors have attracted attention from the viewpoints of being excellent in instantaneous charge / discharge characteristics, obtaining high output characteristics, and being easy to handle.
- the capacitor includes a positive electrode, a negative electrode, and an electrolyte.
- a negative electrode including a porous carbon material that adsorbs and desorbs cations in an electrolyte is used as a negative electrode active material.
- a lithium ion capacitor a negative electrode including a material that occludes and releases lithium ions in an electrolyte is used as a negative electrode active material.
- polarizable electrodes using activated carbon as a positive electrode active material are used as positive electrodes (see Patent Documents 1 and 2).
- Activated carbon develops capacity by a non-Faraday reaction that adsorbs and desorbs ions such as anions contained in the electrolyte.
- the ion adsorption property (and desorption property) of the activated carbon is high, it becomes easy to ensure a high capacity and / or high output.
- the activation treatment introduces oxygen-containing functional groups such as hydroxyl group, carboxyl group, carbonyl group, acid anhydride group, ether group, and lactone group into activated carbon.
- a lithium ion capacitor is charged / discharged in a range where the upper limit voltage of charging is up to about 3.8V, and an EDLC is charged / discharged in a range where the upper limit voltage of charging is up to about 2.5V.
- the upper limit voltage of charging exceeds these voltage values and becomes higher than a predetermined value, among the oxygen-containing functional groups introduced into the activated carbon, in particular, the carboxyl group becomes extremely reactive with the electrolyte, and the electrolyte is decomposed. And capacity decreases. Such a decrease in capacity becomes prominent when the capacitor is repeatedly charged and discharged, so that the cycle characteristics deteriorate.
- the objective of this invention is providing the capacitor which is excellent in cycling characteristics, even if it raises the upper limit voltage of charging / discharging.
- One aspect of the present invention is a capacitor including a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and an electrolyte, wherein the capacitor is a lithium ion capacitor, and the positive electrode is a positive electrode
- the present invention relates to a capacitor having a carboxyl group desorption amount per unit mass of the activated carbon of 0.03 ⁇ mol / g or less when heated and having a charge / discharge upper limit voltage of 4.2 V or more.
- Another aspect of the present invention is a capacitor including a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and an electrolyte, wherein the capacitor is an EDLC, and the positive electrode is a positive electrode
- the present invention relates to a capacitor having a carboxyl group desorption amount per unit mass of the activated carbon of 0.03 ⁇ mol / g or less when heated and having a charge / discharge upper limit voltage of 3.3 V or more.
- Still another aspect of the present invention is a method for charging and discharging a capacitor, wherein the capacitor is a lithium ion capacitor, the positive electrode is a positive electrode current collector, and a positive electrode active material supported on the positive electrode current collector. And the positive electrode active material contains activated carbon, the activated carbon has a carboxyl group, and desorption of carboxyl groups per unit mass of the activated carbon when heated from 300 ° C. to 500 ° C. It is related with the charging / discharging method including the process of charging / discharging the said capacitor by the upper limit voltage of 4.2V or more whose quantity is 0.03 micromol / g or less.
- Another aspect of the present invention is a method for charging and discharging a capacitor, wherein the capacitor is an EDLC, the positive electrode includes a positive electrode current collector, and a positive electrode active material supported on the positive electrode current collector. And the positive electrode active material contains activated carbon, the activated carbon has a carboxyl group, and the desorption amount of the carboxyl group per unit mass of the activated carbon when heated from 300 ° C. to 500 ° C. is 0
- the charge / discharge method includes a step of charging and discharging the capacitor at an upper limit voltage of 3.3 V or higher.
- the present invention it is possible to obtain a high capacity maintenance ratio even when charging and discharging are repeated in a capacitor having an increased upper limit voltage for charging and discharging. That is, a capacitor having excellent cycle characteristics can be provided.
- FIG. 1 is a longitudinal sectional view schematically showing a capacitor according to an embodiment of the present invention. It is a lineblock diagram showing roughly the charge and discharge system concerning one embodiment of the present invention.
- the first embodiment of the present invention is (1) a capacitor including a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and an electrolyte, wherein the capacitor is a lithium ion capacitor,
- the positive electrode includes a positive electrode current collector and a positive electrode active material supported on the positive electrode current collector, the positive electrode active material includes activated carbon, the activated carbon has a carboxyl group, and has a temperature of 300 ° C.
- the present invention relates to a capacitor having a carboxyl group elimination amount per unit mass of the activated carbon of 0.03 ⁇ mol / g or less and a charge / discharge upper limit voltage of 4.2 V or more when heated to 500 ° C.
- a second embodiment of the present invention is a capacitor including (2) a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and an electrolyte, wherein the capacitor is an EDLC, and the positive electrode Includes a positive electrode current collector and a positive electrode active material supported on the positive electrode current collector, the positive electrode active material includes activated carbon, the activated carbon has a carboxyl group, and has a temperature of 300 ° C. to 500 ° C.
- the present invention relates to a capacitor having a carboxyl group desorption amount per unit mass of the activated carbon of 0.03 ⁇ mol / g or less and a charge / discharge upper limit voltage of 3.3 V or more when heated to a temperature up to.
- Activated carbon used as a positive electrode active material for a lithium ion capacitor or EDLC exhibits capacity by adsorbing and desorbing ions such as anions contained in the electrolyte. From the viewpoint of enhancing the adsorptivity of ions, it is advantageous to use activated carbon that has been activated.
- the adsorptivity of ions can be increased by controlling the pore diameter of activated carbon and / or increasing the specific surface area.
- the activation treatment introduces functional groups such as oxygen-containing groups into the activated carbon, which may affect the capacitor performance. Examples of such oxygen-containing groups include hydroxyl groups (including phenolic hydroxyl groups), carboxyl groups, carbonyl groups, acid anhydride groups, ether groups, lactone groups, and quinone groups.
- the upper limit voltage of charge / discharge increases, the potential of the positive electrode during charge increases, and side reactions involving oxygen-containing groups contained in activated carbon tend to occur. In such a side reaction, water and / or gas is generated, and the performance of the capacitor may be impaired.
- the upper limit voltage of charge / discharge is increased to 4.2 V or more for a lithium ion capacitor and 3.3 V or more for EDLC, an electrolyte is caused by a side reaction between a hydroxyl group of a carboxyl group and an electrolyte among oxygen-containing functional groups. Is decomposed, and the capacitance of the capacitor decreases.
- the capacitor is required to have long-term reliability. However, if the upper limit voltage for charging / discharging is increased to the above voltage or more, the long-term reliability is likely to be impaired.
- activated carbon with reduced carboxyl groups that is, activated carbon having a carboxyl group elimination amount of 0.03 ⁇ mol / g or less per unit mass of activated carbon.
- the decomposition reaction of the electrolyte involving the carboxyl group can be suppressed. Therefore, a capacitor having excellent cycle characteristics can be provided.
- production of gas is suppressed because the decomposition reaction of electrolyte is suppressed, As a result, the increase in internal resistance can be suppressed.
- the carboxyl group is desorbed from the activated carbon in a temperature range of about 300 to 500 ° C. to generate carbon dioxide, thereby reducing the weight of the activated carbon. Therefore, the amount of carboxyl groups desorbed from the activated carbon can be evaluated based on the mass reduction amount (that is, the amount of carbon dioxide desorption) at this time. In addition, when 1 mol of carboxyl groups are eliminated, 1 mol of water and 1 mol of carbon dioxide are generated.
- the amount of carboxyl group desorption ( ⁇ mol / g) is determined by heating a predetermined amount (initial mass) of activated carbon (preferably activated carbon after dehydration) from 300 ° C. to 500 ° C., and reducing the mass of activated carbon at this time
- the amount ( ⁇ mol) of carbon dioxide generated from the amount can be obtained and calculated by dividing by the initial mass (g) of the activated carbon.
- the amount of carbon dioxide generated from activated carbon during heating at elevated temperature can be measured using, for example, a temperature-desorption (TPD) method.
- TPD temperature-desorption
- the desorbed gas can be detected using, for example, a quadrupole mass spectrometer.
- the temperature raising rate is not particularly limited, but may be, for example, 1 to 10 ° C./min.
- the dehydration treatment of the activated carbon can be performed, for example, by heating the activated carbon at a temperature of 150 ° C. or lower.
- the positive electrode current collector preferably has a three-dimensional network skeleton.
- the porosity is larger than in the case of using a metal foil current collector. Therefore, even if gas is generated in the pores (voids) of the positive electrode due to, for example, aging in the manufacturing process of the capacitor, the gas is easily released, and the gas can be completely discharged during manufacturing.
- the embodiment of the present invention even if the upper limit voltage of charging / discharging is increased, gas generation during charging / discharging can be suppressed, but even if gas is generated during charging / discharging, such a positive electrode current collector can be used. In the positive electrode used, since gas is easily dispersed, an increase in internal resistance can be remarkably suppressed. It is also advantageous from the viewpoint of increasing the capacity of the capacitor.
- the thickness of the positive electrode is preferably 500 to 2000 ⁇ m.
- the thickness of the positive electrode is large as described above, the volume of voids in the positive electrode is increased, so that even if gas is generated, it is easily dispersed. Therefore, an increase in internal resistance can be further suppressed.
- the activated carbon preferably has a specific surface area of 1200 to 3500 m 2 / g. Activated carbon having such a specific surface area tends to increase the amount of elimination of oxygen-containing functional groups such as carboxyl groups. By reducing the amount of carboxyl groups eliminated, activated carbon having such a specific surface area can be used, so that high capacity and / or high output can be easily obtained.
- the upper limit voltage is preferably 4.5 V or more.
- a third embodiment of the present invention is a method for charging and discharging a capacitor, wherein the capacitor is a lithium ion capacitor, and the positive electrode is carried on a positive electrode current collector and the positive electrode current collector.
- a positive electrode active material includes activated carbon, the activated carbon has a carboxyl group, and the number of carboxyl groups per unit mass of the activated carbon when heated from 300 ° C. to 500 ° C.
- the present invention relates to a charge / discharge method including a step of charging / discharging the capacitor at an upper limit voltage of 4.2 V or more, wherein a desorption amount is 0.03 ⁇ mol / g or less.
- the lithium ion capacitor can be repeatedly charged and discharged even at the upper limit voltage of 4.2 V or more, and the cycle characteristics are reduced. Can be suppressed.
- the fourth embodiment of the present invention is a method for charging and discharging a capacitor, wherein the capacitor is an EDLC, the positive electrode is a positive electrode current collector, and a positive electrode active supported on the positive electrode current collector. And the positive electrode active material contains activated carbon, the activated carbon has a carboxyl group, and desorption of carboxyl groups per unit mass of the activated carbon when heated from 300 ° C. to 500 ° C. It is related with the charging / discharging method including the process of charging / discharging the said capacitor with the upper limit voltage of 3.3V or more whose quantity is 0.03 micromol / g.
- EDLC since decomposition of the electrolyte due to the carboxyl group contained in the activated carbon is suppressed, EDLC can be repeatedly charged and discharged even at an upper limit voltage of 3.3 V or more, and deterioration in cycle characteristics can be suppressed. .
- the capacitor according to the embodiment of the present invention includes a lithium ion capacitor and an EDLC.
- Each capacitor includes a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and an electrolyte.
- the positive electrode includes a positive electrode current collector and a positive electrode active material supported on the positive electrode current collector.
- the positive electrode may include a positive electrode mixture containing a positive electrode active material and a positive electrode current collector carrying the positive electrode mixture.
- a common positive electrode can be used for the lithium ion capacitor and the EDLC.
- the material of the positive electrode current collector is preferably aluminum and / or an aluminum alloy (such as an aluminum-iron alloy and / or an aluminum-copper alloy).
- the positive electrode current collector may be a metal foil or a metal porous body (such as a metal fiber non-woven fabric or a metal porous body sheet).
- the thickness of the metal foil is, for example, 10 to 50 ⁇ m.
- the thickness of the metal porous body is, for example, 100 to 2000 ⁇ m, preferably 500 to 2000 ⁇ m.
- a porous metal body having a three-dimensional network skeleton constitutes a current collector by, for example, plating a resin porous body (resin foam and / or resin nonwoven fabric) having continuous voids. It may be formed by covering with a metal (specifically, the above-exemplified material).
- a porous metal body having a hollow skeleton can be formed by removing the resin in the skeleton by heat treatment or the like.
- the capacitor is aged and / or conditioned and discharged, and is completed by extracting the gas generated at this time.
- the porosity of the positive electrode is large compared to the case of using a metal foil current collector.
- the gas can be extracted completely.
- the porous metal body has a large porosity, a large amount of active material can be supported on the metal porous body, so that the capacitance of the positive electrode can be increased.
- the porosity (or porosity) of the metal porous body having a three-dimensional network skeleton is, for example, 30 to 99% by volume, preferably 50 to 98% by volume, more preferably 80 to 98% by volume, or 90 to 98% by volume. %.
- the specific surface area of the porous metal body having a three-dimensional reticulated skeleton (BET specific surface area), for example, 100 ⁇ 700cm 2 / g, is preferably 150 ⁇ 650cm 2 / g, more preferably 200 ⁇ 600cm 2 / g .
- the positive electrode active material includes activated carbon.
- Activated carbon develops capacity by a non-Faraday reaction that adsorbs and desorbs ions (anions and / or cations) contained in the electrolyte.
- Activated carbon adsorbs and desorbs anions or adsorbs and desorbs cations depending on the positive electrode potential.
- the activated carbon one having a carboxyl group but having a small amount of carboxyl group elimination is used. Specifically, as the activated carbon, those having a carboxyl group elimination amount of 0.03 ⁇ mol / g or less per unit mass of activated carbon when heated from 300 ° C. to 500 ° C. are used.
- the activated carbon contains a carboxyl group
- the upper limit voltage of charge / discharge is increased to 4.2 V or more for a lithium ion capacitor and 3.3 V or more for EDLC
- a side reaction between the hydroxyl group of the carboxyl group and the electrolyte causes The electrolyte decomposes.
- decomposition of the electrolyte can be suppressed even when the upper limit voltage of charge / discharge is increased as described above by using activated carbon with a small amount of carboxyl group elimination. Since it can suppress that an electrolyte is consumed by a side reaction at the time of charging / discharging, the fall of cycling characteristics can be suppressed.
- the amount of carboxyl group elimination is preferably 0.02 ⁇ mol / g or less, more preferably 0.01 ⁇ mol / g or less.
- the activated carbon preferably has as little carboxyl group desorption as possible, but it is difficult to make the desorption amount zero (so that the activated carbon does not contain a carboxyl group).
- the elimination amount of the carboxyl group may be, for example, 0.1 nmol / g or more.
- Activated carbon can be obtained through a step of reducing activated carbide.
- the activated carbide is generally called activated carbon, and commercially available activated carbon may be used, or activated carbon produced according to a known activated carbon production method may be used.
- Any activated carbon is obtained by carbonizing an organic raw material and activating the obtained carbide. Examples of the organic raw material include wood; coconut shell; pulp waste liquid; coal or coal-based pitch obtained by thermal decomposition thereof; heavy oil or petroleum-based pitch obtained by thermal decomposition thereof; and / or phenol resin. . Carbonization can be performed under known conditions.
- Activation can be performed by a known activation method, for example, a gas activation method or a chemical activation method, or a combination of these.
- the carbide is activated by bringing it into contact with a gas such as water vapor, carbon dioxide, and / or oxygen under heating.
- the chemical activation method the carbide is activated by heating it in contact with a known activation chemical.
- the activation chemical include zinc chloride, phosphoric acid, and / or alkali (metal hydroxide such as sodium hydroxide).
- activated carbon activated by steam also referred to as steam activated charcoal
- alkali activated charcoal also referred to as alkali activated charcoal
- Activation can be performed under known conditions.
- Alkaline activated charcoal has a large specific surface area, so it is advantageous from the viewpoint of high capacity and high output.
- an oxygen-containing functional group such as a carboxyl group is easily introduced into the carbide, so that a side reaction easily occurs in the capacitor.
- steam activated charcoal has a small specific surface area, since the introduction amount of oxygen-containing functional groups such as carboxyl groups is small, steam activated charcoal is widely used as a positive electrode active material for capacitors.
- by further reducing the activated carbide it is possible to significantly reduce the amount of carboxyl group elimination even when using alkali activated carbon, and the carboxyl group in the capacitor is involved. Side reactions can be greatly suppressed. Therefore, since the large specific surface area of alkali activated carbon can be used effectively, it is advantageous from the viewpoint of high capacity and / or high output.
- Reduction of the activated carbide can be performed by heating the activated carbide (for example, steam activated charcoal and / or alkali activated charcoal) in a reducing atmosphere.
- the reducing atmosphere is preferably an reducing gas atmosphere such as hydrogen gas.
- a reducing gas may be used, or a mixture of a reducing gas and an inert gas (such as nitrogen gas and / or argon gas) may be used.
- the content of the reducing gas in the mixture can be appropriately selected from the range of 1 to 99% by volume, for example, and is preferably 1 to 40% by volume or 1 to 10% by volume.
- the reduction step may be performed under pressure, but is preferably performed under normal pressure (for example, 0.10 ⁇ 0.01 MPa).
- the heating temperature in the reduction step is, for example, 500 to 900 ° C., preferably 600 to 800 ° C. By reducing at such a temperature, the amount of carboxyl groups eliminated can be greatly reduced.
- the alkali remains in the activated carbon obtained by reducing the alkali activated carbon.
- the alkali content of such activated carbon is, for example, 20 to 500 ppm on a mass basis.
- the specific surface area (BET specific surface area) of the activated carbon is, for example, 800 to 3500 m 2 / g, preferably 1200 to 3500 m 2 / g, and more preferably 1600 to 3200 m 2 / g or 1800 to 3000 m 2 / g.
- the average particle diameter of the activated carbon is not particularly limited, but is preferably 20 ⁇ m or less, more preferably 3 to 15 ⁇ m. In the present specification, the average particle size means a volume-based median diameter D 50 in the particle size distribution obtained by laser diffraction particle size distribution measurement.
- the positive electrode active material can include an active material other than activated carbon, for example, porous carbon (also referred to as nanoporous carbon) having fine pores on the order of sub nm to sub ⁇ m, and / or carbon nanotubes, and mainly includes activated carbon. It is preferable.
- the ratio of activated carbon in the positive electrode active material is preferably 80 to 100% by mass, and more preferably 90 to 100% by mass.
- the positive electrode active material may be composed only of activated carbon.
- the positive electrode can be obtained, for example, by supporting a positive electrode active material (or a positive electrode mixture) on a positive electrode current collector. More specifically, it is obtained by applying or filling a positive electrode mixture containing at least a positive electrode active material to a positive electrode current collector, drying, and compressing (or rolling) the dried product in the thickness direction as necessary. It is done.
- the positive electrode mixture can contain a conductive additive and / or a binder as optional components.
- the positive electrode mixture is used in the form of a slurry containing the components of the positive electrode mixture (positive electrode active material, conductive auxiliary agent and / or binder, etc.) and a dispersion medium.
- the dispersion medium for example, an organic solvent such as N-methyl-2-pyrrolidone (NMP) and / or water is used.
- the type of the conductive auxiliary agent is not particularly limited.
- carbon black such as acetylene black and ketjen black; graphite (natural graphite such as flaky graphite and earthy graphite; artificial graphite and the like); conductive such as ruthenium oxide Conductive compounds; and conductive fibers such as carbon fibers and metal fibers.
- a conductive support agent can be used individually by 1 type or in combination of 2 or more types. From the viewpoint of ensuring high conductivity and capacity, the amount of the conductive auxiliary is, for example, 1 to 20 parts by mass, preferably 5 to 15 parts by mass with respect to 100 parts by mass of the positive electrode active material.
- the type of the binder is not particularly limited.
- a fluorine resin such as polyvinylidene fluoride (PVDF); a polyolefin resin; a rubbery polymer such as styrene butadiene rubber; a polyvinyl pyrrolidone; a polyvinyl alcohol; and a cellulose derivative [for example, , Cellulose ethers (carboxyalkylcelluloses such as carboxymethylcellulose and sodium salts thereof and salts thereof (such as alkali metal salts and / or ammonium salts)), and the like.
- a binder can be used individually by 1 type or in combination of 2 or more types.
- the amount of the binder is not particularly limited, but can be selected from the range of, for example, 0.1 to 15 parts by mass per 100 parts by mass of the positive electrode active material from the viewpoint of easily ensuring high binding properties and capacity, and is preferably about 0.1. 5 to 10 parts by mass.
- the thickness of the positive electrode can be appropriately selected from the range of 50 to 2000 ⁇ m, for example.
- the thickness of the positive electrode is, for example, 50 to 500 ⁇ m or 50 to 300 ⁇ m.
- the thickness of the positive electrode is, for example, 100 to 2000 ⁇ m, preferably 500 to 2000 ⁇ m.
- the negative electrode includes a negative electrode active material.
- the negative electrode can include a negative electrode active material and a negative electrode current collector carrying the negative electrode active material.
- As the material of the negative electrode current collector copper, copper alloy, nickel, nickel alloy, stainless steel, aluminum, and / or aluminum alloy are preferable.
- As the negative electrode current collector a metal foil may be used, or a metal porous body may be used from the viewpoint of increasing the capacity of the electricity storage device.
- the porous metal body is preferably a porous metal body having a three-dimensional network skeleton (particularly, a hollow skeleton) similar to the positive electrode current collector.
- the porosity and specific surface area of the metal porous body can be appropriately selected from the ranges exemplified for the metal porous body of the positive electrode current collector.
- the porous metal body as the negative electrode current collector can be produced according to the case of the positive electrode current collector, using the above materials when the resin porous body is coated with metal.
- the negative electrode active material is preferably a material that reversibly carries cations contained in the electrolyte. Such materials include materials that occlude and release (or insert and desorb) cations (ie, materials that develop capacity through Faraday reactions), and materials that adsorb and desorb cations (ie, non-Faraday reactions). The material which expresses capacity) can be illustrated.
- a negative electrode active material including a material that develops capacity by a Faraday reaction is used in EDLC, a negative electrode active material that includes a material that develops capacity by a Faraday reaction and / or a material that develops capacity by a non-Faraday reaction. Substance is used.
- Examples of the negative electrode active material used in the lithium ion capacitor include materials that occlude and release (or insert and desorb) lithium ions contained in the electrolyte.
- Examples of such materials include carbonaceous materials that occlude and release (or insert and desorb) lithium ions, lithium titanium oxides [for example, lithium titanium oxides (spinel type lithium titanium oxides such as lithium titanate) Etc.)], silicon oxide, silicon alloy, tin oxide, and tin alloy.
- Examples of the carbonaceous material include graphitizable carbon (soft carbon), non-graphitizable carbon (hard carbon), and carbonaceous material having a graphite type crystal structure.
- a negative electrode active material may be used individually by 1 type, and may be used in combination of 2 or more type.
- the negative electrode active material used in the lithium ion capacitor preferably has a theoretical capacity of 300 mAh / g or more.
- carbonaceous materials are preferred, and carbonaceous materials having a graphite-type crystal structure and / or hard carbon are particularly preferred.
- the graphite-type crystal structure means a layered crystal structure, and examples thereof include a cubic crystal structure and a rhombohedral crystal structure.
- Examples of the carbonaceous material having a graphite-type crystal structure include natural graphite (such as flake graphite), artificial graphite, and / or graphitized mesocarbon microspheres.
- Examples of the negative electrode active material used in EDLC include activated carbon, the aforementioned nanoporous carbon, and carbon nanotube.
- a negative electrode active material can be used individually by 1 type or in combination of 2 or more types.
- the nanoporous carbon those known for use in capacitors can be used, and examples thereof include those obtained by heating a metal carbide such as silicon carbide and / or titanium carbide in an atmosphere containing chlorine gas. .
- the heating temperature can be selected from a range of 1000 to 2000 ° C., for example, and is 1000 to 1500 ° C.
- the negative electrode active material used in EDLC preferably contains activated carbon.
- the activated carbon known ones used for capacitors can be used, and examples thereof include activated carbons of organic raw materials and / or activated carbides of organic materials.
- the activated carbon the activated carbon described for the positive electrode active material can also be used.
- an organic material used as the raw material of activated carbon what was illustrated about the activated carbon of a positive electrode active material is mentioned.
- the specific surface area and average particle size of the activated carbon may be in the ranges described for the activated carbon of the positive electrode active material.
- the negative electrode can be obtained by supporting a negative electrode active material (or a negative electrode mixture) on the negative electrode current collector, in the same manner as in the case of the positive electrode.
- the negative electrode mixture can contain a conductive additive and / or a binder as optional components.
- the negative electrode mixture is used in the form of a slurry containing the components of the negative electrode mixture (negative electrode active material, conductive auxiliary agent and / or binder, etc.) and a dispersion medium.
- a dispersion medium As a dispersion medium, a conductive support agent, and a binder, it can respectively select from what was illustrated about the positive electrode suitably.
- the amounts of the conductive additive and the binder with respect to 100 parts by mass of the negative electrode active material can be appropriately selected from the ranges of the amounts of the conductive auxiliary and the binder with respect to 100 parts by mass of the positive electrode active material.
- the thickness of the negative electrode can be appropriately selected from the thickness range exemplified for the positive electrode, and is, for example, 100 to 2000 ⁇ m.
- the separator has ion permeability, is interposed between the positive electrode and the negative electrode, and physically separates them to prevent a short circuit.
- the separator has a porous structure and allows ions to pass through by holding an electrolyte in the pores.
- polyolefin such as polyethylene and / or polypropylene
- polyester such as polyethylene terephthalate
- polyamide such as polyethylene terephthalate
- polyamide polyamide
- polyimide polyimide
- cellulose and / or glass fiber
- the average pore diameter of the separator is not particularly limited, and is, for example, about 0.01 to 5 ⁇ m.
- the thickness of the separator is not particularly limited, and is about 10 to 100 ⁇ m, for example.
- the porosity of the separator is not particularly limited and is, for example, 40 to 80% by volume, preferably 50 to 70% by volume.
- the electrolyte includes cations and anions.
- a nonaqueous electrolyte is preferably used as the electrolyte.
- the electrolyte of each capacitor will be described below.
- the electrolyte of each capacitor has lithium ion conductivity. In such an electrolyte, the cation contains at least lithium ions.
- the non-aqueous electrolyte include an electrolyte (organic electrolyte) obtained by dissolving a salt (lithium salt) of lithium ions and anions in a non-aqueous solvent (or organic solvent), and a cation and an anion containing at least lithium ions. An ionic liquid or the like is used.
- the organic electrolyte can contain an ionic liquid and / or an additive in addition to the non-aqueous solvent (organic solvent) and the lithium salt.
- the total content of the non-aqueous solvent and the lithium salt in the electrolyte is, for example, It is 60% by mass or more, preferably 75% by mass or more, and more preferably 85% by mass or more.
- the total content of the nonaqueous solvent and the lithium salt in the electrolyte may be, for example, 100% by mass or less, or 95% by mass or less. These lower limit values and upper limit values can be arbitrarily combined.
- the total content of the nonaqueous solvent and the lithium salt in the electrolyte may be, for example, 60 to 100% by mass, or 75 to 95% by mass.
- the ionic liquid is synonymous with a molten salt (molten salt) and is a liquid ionic substance composed of an anion and a cation.
- the electrolyte can contain a nonaqueous solvent and / or an additive in addition to the ionic liquid containing a cation and an anion containing lithium ions, but the content of the ionic liquid in the electrolyte Is preferably 60% by mass or more, and more preferably 70% by mass or more.
- the content of the ionic liquid in the electrolyte may be 80% by mass or more, or 90% by mass or more.
- the content of the ionic liquid in the electrolyte is 100% by mass or less.
- an electrolyte containing a non-aqueous solvent organic solvent
- an electrolyte containing an ionic liquid is preferably used, and an electrolyte containing an ionic liquid and a nonaqueous solvent may be used.
- concentration of the lithium salt or lithium ion in the electrolyte can be appropriately selected from the range of 0.3 to 5 mol / L, for example.
- the kind of the anion (first anion) constituting the lithium salt is not particularly limited.
- anion of fluorine-containing acid fluorine-containing phosphate anion such as hexafluorophosphate ion (PF 6 ⁇ ); tetrafluoroborate ion; Fluorine-containing borate anions such as (BF 4 ⁇ )), anions of chlorine-containing acids (such as perchlorate ions), anions of oxygen acids having an oxalate group [bis (oxalato) borate ions (B (C 2 O 4) -) 2) oxalatoborate ions such as; and tris (oxalato) phosphate ions (P (C 2 O 4) 3 -) oxa Lato phosphate ions, etc.], such as the anion of fluoroalkanesulfonic acid [trifluoromethanesulfonate ion (CF 3 SO 3 ⁇ ), etc.], and bissulf
- bissulfonylamide anion examples include bis (fluorosulfonyl) amide anion (FSA ⁇ : bis (fluorosulfonyl) amide anion), bis (trifluoromethylsulfonyl) amide anion (TFSA ⁇ : bis (trifluoromethylsulfamide) amide anion.
- the non-aqueous solvent is not particularly limited, and a known non-aqueous solvent used for a lithium ion capacitor can be used.
- Non-aqueous solvents include, for example, cyclic carbonates such as ethylene carbonate, propylene carbonate, and butylene carbonate; chain carbonates such as dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate; and ⁇ -butyrolactone.
- a cyclic carbonate or the like can be preferably used.
- a non-aqueous solvent may be used individually by 1 type, and may be used in combination of 2 or more type.
- the ionic liquid contains a molten salt of a cation and an anion (second anion).
- the ionic liquid may contain a kind of molten salt, or may contain two or more kinds of molten salts having different types of cations and / or second anions.
- a bissulfonylamide anion is preferably used as the second anion.
- the bissulfonylamide anion can be selected from those similar to those exemplified for the first anion.
- the cation constituting the ionic liquid contains at least lithium ions, and may contain lithium ions (first cations) and second cations.
- first cations lithium ions
- second cations the inorganic cation different from a lithium ion, an organic cation, etc.
- examples of the inorganic cation include alkali metal ions (sodium ions, potassium ions, etc.) other than lithium ions, alkaline earth metal ions (magnesium ions, calcium ions, etc.), ammonium ions, and the like.
- the second cation may be an inorganic cation, but is preferably an organic cation.
- the ionic liquid may contain one type of second cation, or may contain two or more types in combination.
- Organic cations include cations derived from aliphatic amines, alicyclic amines or aromatic amines (for example, quaternary ammonium cations), and cations having nitrogen-containing heterocycles (that is, cations derived from cyclic amines). And nitrogen-containing organic onium cations; sulfur-containing onium cations; and phosphorus-containing onium cations.
- nitrogen-containing organic onium cations those having pyrrolidine, pyridine, or imidazole as the quaternary ammonium cation and the nitrogen-containing heterocyclic skeleton are particularly preferable.
- nitrogen-containing organic onium cations include tetraalkylammonium cations (TEA + : tetraethylammonium cation), tetraalkylammonium cations such as methyltriethylammonium cation (TEMA + : methyltriethylammonium cation); 1-methyl-1-propylpyrrolidinium Cations (MPPY + : 1-methyl-1-propylpyrrolidinium cation), 1-butyl-1-methylpyrrolidinium cation (MBPY + : 1-butyl-1-methylpyrrolidinium cation); 1-ethyl-3-methylimidazolium cation (EMI +: 1-ethyl- 3-methylimidazo ium cation), and 1-butyl-3-methylimidazolium cation (BMI +: 1-buthyl- 3-methylimidazolium cation) and the like.
- TEA + t
- the electrolyte used for EDLC is preferably a non-aqueous electrolyte.
- the electrolyte include an electrolyte in which a salt of a cation (third cation) and an anion (third anion) is dissolved in a non-aqueous solvent (or an organic solvent), and a cation (fourth cation) and an anion (fourth anion).
- a nonaqueous electrolyte such as an ionic liquid is preferably used.
- an organic cation and / or an inorganic cation are used, respectively.
- Examples of the organic cation and the inorganic cation include those exemplified for the second cation.
- Each of the third and fourth cations preferably includes an organic cation.
- a quaternary ammonium cation such as TEA + and / or TEMA + is preferable.
- As the fourth cation a cation having an imidazole skeleton such as EMI + is preferable.
- the concentration of the third cation or the fourth cation in the electrolyte can be appropriately selected from a range of 0.3 to 5 mol / L, for example.
- the third anion can be appropriately selected from those exemplified as the first anion.
- a nonaqueous solvent it can select suitably from what was illustrated about the electrolyte of the lithium ion capacitor.
- the total content of the salt of the third cation and the third anion in the electrolyte and the content of the nonaqueous solvent can be appropriately selected from the range described for the total content of the nonaqueous solvent and the lithium salt in the electrolyte of the lithium ion capacitor. .
- the fourth anion contained in the ionic liquid can be appropriately selected from those exemplified as the second anion described above.
- the fourth anion preferably includes at least a bissulfonylamide anion.
- Content of the ionic liquid in electrolyte can be suitably selected from the range illustrated about the lithium ion capacitor.
- the capacitor according to the embodiment of the present invention includes, for example, (a) a step of forming an electrode group with a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode; It can manufacture by passing through the process accommodated in.
- the capacitor assembled in step (c) is usually subjected to an activation treatment step (d).
- the capacitor In the activation process step (d), the capacitor is aged (or heat-treated) and / or conditioned and discharged to allow stable charge and discharge. By performing aging treatment and / or break-in charge / discharge, gas is generated in the capacitor. Therefore, degassing treatment is performed in step (d).
- the aging treatment is performed after the pre-doping.
- Step (d) can include a pre-doping step, an aging treatment step, a break-in charge / discharge step, and / or a degassing step.
- the degassing process can be performed by discharging the gas generated in the capacitor out of the capacitor through a valve (such as a degassing valve and / or a safety valve described later) provided in the capacitor case.
- a valve such as a degassing valve and / or a safety valve described later
- pre-doping means that lithium ions are previously stored in the negative electrode before the capacitor is operated.
- FIG. 1 is a longitudinal sectional view schematically showing a capacitor according to an embodiment of the present invention.
- the capacitor includes a stacked electrode group, an electrolyte (not shown), and a rectangular aluminum cell case 10 for housing them.
- the cell case 10 includes a bottomed container body 12 having an upper opening and a lid 13 that closes the upper opening.
- the stacked electrode group is formed by stacking a plurality of cells by forming a cell by overlapping the separator 1 between the positive electrode 2 and the negative electrode 3.
- the formed electrode group is inserted into the container body 12 of the cell case 10. Thereafter, a step of injecting an electrolyte into the container body 12 and impregnating the electrolyte in the gaps of the separator 1, the positive electrode 2 and the negative electrode 3 constituting the electrode group is performed.
- a safety valve 16 is provided for releasing gas generated inside when the internal pressure of the cell case 10 rises.
- An external positive terminal 14 that penetrates the lid 13 is provided near the one side of the lid 13 with the safety valve 16 in the center, and an external that penetrates the lid 13 is located near the other side of the lid 13.
- a negative terminal is provided.
- the stacked electrode group is composed of a plurality of positive electrodes 2, a plurality of negative electrodes 3, and a plurality of separators 1 interposed therebetween, all in the form of a rectangular sheet.
- the separator 1 is formed in a bag shape so as to surround the positive electrode 2, but the form of the separator is not particularly limited.
- the plurality of positive electrodes 2 and the plurality of negative electrodes 3 are alternately arranged in the stacking direction within the electrode group.
- a positive electrode lead piece 2 a may be formed at one end of each positive electrode 2.
- the plurality of positive electrodes 2 are connected in parallel by bundling the positive electrode lead pieces 2 a of the plurality of positive electrodes 2 and connecting them to the external positive terminal 14 provided on the lid 13 of the cell case 10.
- a negative electrode lead piece 3 a may be formed at one end of each negative electrode 3.
- the plurality of negative electrodes 3 are connected in parallel by bundling the negative electrode lead pieces 3 a of the plurality of negative electrodes 3 and connecting them to the external negative terminal provided on the lid 13 of the cell case 10.
- the bundle of the positive electrode lead pieces 2a and the bundle of the negative electrode lead pieces 3a are desirably arranged on the left and right sides of one end face of the electrode group with an interval so as to avoid mutual contact.
- the external positive terminal 14 and the external negative terminal are both columnar, and at least a portion exposed to the outside has a thread groove.
- a nut 7 is fitted in the screw groove of each terminal, and the nut 7 is fixed to the lid 13 by rotating the nut 7.
- a flange 8 is provided in a portion of each terminal accommodated in the cell case 10, and the flange 8 is fixed to the inner surface of the lid 13 via a washer 9 by the rotation of the nut 7. .
- the cell case may be composed of a polymer film, an aluminum laminate film, or the like, or may be made of a metal such as aluminum, aluminum alloy, iron, or stainless steel (that is, a metal can).
- the metal cell case may be plated as necessary.
- the shape of the cell case is not particularly limited, and may be a cylindrical shape whose cross section parallel to the bottom surface of the cell case is a circle, an ellipse, or a square.
- the electrode group is not limited to a laminated type, and may be formed by winding a positive electrode and a negative electrode through a separator.
- the dimension of the negative electrode may be made larger than that of the positive electrode from the viewpoint of preventing deposition of metallic lithium on the negative electrode.
- the capacitor according to the embodiment of the present invention can be repeatedly charged / discharged even if the upper limit voltage of charging / discharging is increased, and the deterioration of the cycle characteristics can be suppressed. Since the upper limit voltage of charge / discharge can be increased, the capacity of the active material can be used effectively, and the capacity of the capacitor can be increased.
- a capacitor charging / discharging method includes a step of charging / discharging a capacitor with an upper limit voltage V u .
- the upper limit voltage V u is 4.2 V or higher, preferably 4.3 V or higher, more preferably 4.4 V or higher or 4.5 V or higher. Although an upper limit voltage can also be made into the value exceeding 5V, it is preferable that it is 5V or less. These lower limit values and upper limit values can be arbitrarily combined.
- the upper limit voltage of charging / discharging may be, for example, 4.2-5V, 4.3-5V, or 4.5-5V.
- the upper limit voltage V u is 3.3 V or higher, preferably 3.4 V or higher, more preferably 3.5 V or higher.
- the upper limit voltage V u is preferably 4 V or less.
- the upper limit voltage for charging and discharging the capacitor cannot be determined freely by the user or the like, but is a characteristic of the capacitor determined at the time of designing the capacitor according to the capacitor components.
- Charging and discharging of the capacitor is usually performed within a preset voltage range. Specifically, the capacitor is charged until a preset upper limit voltage is reached, and the capacitor is discharged until a preset end voltage is reached.
- Charging and discharging are usually performed by a charge control unit and a discharge control unit in a charge / discharge system including a capacitor.
- Embodiments of the present invention also include a charge / discharge system including a capacitor, a charge control unit that controls charging of the capacitor, and a discharge control unit that controls discharge of the capacitor.
- the discharge control unit may include a load device that consumes power supplied from the capacitor.
- FIG. 2 is a block diagram schematically showing a charge / discharge system according to an embodiment of the present invention.
- the charge / discharge system 100 includes a capacitor 101, a charge / discharge control unit 102 that controls charge / discharge of the capacitor 101, and a load device 103 that consumes power supplied from the capacitor 101.
- the charge / discharge control unit 102 includes a charge control unit 102a that controls current and / or voltage when the capacitor 101 is charged, and a discharge control unit 102b that controls current and / or voltage when the capacitor 101 is discharged. including.
- the charge control unit 102 a is connected to the external power source 104 and the capacitor 101, and the discharge control unit 102 b is connected to the capacitor 101.
- a load device 103 is connected to the capacitor 101.
- a capacitor including a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and an electrolyte, wherein the capacitor is an EDLC, the positive electrode is a positive electrode current collector, and the positive electrode current collector
- a positive active material supported on the body the positive active material includes activated carbon, the activated carbon has a carboxyl group, and the unit mass of the activated carbon when heated from 300 ° C. to 500 ° C.
- Capacitor having an upper limit voltage of charge / discharge of 3.3 V or more, wherein the amount of released carboxyl groups per unit is 0.03 ⁇ mol / g or less.
- the positive electrode current collector has a three-dimensional network skeleton, the thickness of the positive electrode is 500 to 2000 ⁇ m, and the specific surface area of the activated carbon is 1600 to 3200 m 2 / It is preferable that the activated carbon contains an alkali, and the content of the alkali in the activated carbon is 20 to 500 ppm. In such a capacitor, an increase in internal resistance is suppressed, and cycle characteristics can be further improved. It is also advantageous from the viewpoint of increasing capacity and / or increasing output.
- Appendix 4 A charge / discharge system including the capacitor according to Appendix 1 or 2, the charge control unit that controls charging of the capacitor, and the discharge control unit that controls discharge of the capacitor.
- the charge control unit that controls charging of the capacitor
- the discharge control unit that controls discharge of the capacitor.
- the upper limit voltage of charging / discharging of the capacitor is increased to 4.2 V or higher with a lithium ion capacitor and 3.3 V or higher with EDLC, the decomposition reaction of an electrolyte involving a carboxyl group is prevented.
- the cycle characteristics of the capacitor can be improved.
- the foam having the conductive layer formed on the surface was immersed in a molten salt aluminum plating bath, and a direct current having a current density of 3.6 A / dm 2 was applied for 90 minutes to form an aluminum layer.
- the mass of the aluminum layer per apparent area of the foam was 150 g / m 2 .
- the molten salt aluminum plating bath contained 33 mol% 1-ethyl-3-methylimidazolium chloride and 67 mol% aluminum chloride, and the temperature was 40 ° C.
- the foam with the aluminum layer formed on the surface was immersed in a lithium chloride-potassium chloride eutectic molten salt at 500 ° C., and a negative potential of ⁇ 1 V was applied for 30 minutes to decompose the foam.
- the obtained aluminum porous body was taken out of the molten salt, cooled, washed with water, and dried to obtain a current collector.
- the obtained current collector has a three-dimensional network-like porous structure in which pores communicated, reflecting the pore shape of the foam, has a porosity of 94% by volume, and an average pore diameter of 550 ⁇ m.
- the specific surface area (BET specific surface area) by the BET method was 350 cm 2 / g, and the thickness was 1100 ⁇ m.
- the three-dimensional mesh-like aluminum skeleton had a communication hole-like cavity formed by removing the foam.
- the alkali content of the obtained reduced product (activated carbon) was 300 ppm.
- About 15 g of the obtained reduced product (activated carbon) was kept at 150 ° C. for 1 hour to remove moisture, and the mass (initial mass) mi (g) at this time was measured.
- the temperature was raised from 150 ° C. to 950 ° C. at a rate of 5 ° C./min, and the amount of carbon dioxide ( ⁇ mol) generated in this temperature range was determined from the mass reduction amount of the activated carbon in the range of 300 to 500 ° C.
- the amount of carboxyl groups eliminated in the activated carbon was determined and found to be 0.02 ⁇ mol / g.
- (B-2) Production of Positive Electrode and Negative Electrode
- An electrode mixture slurry was prepared by mixing with stirring using a mixer.
- the mass ratio of the active material, acetylene black, and PVDF was 100: 10.7: 5.7.
- the obtained electrode mixture slurry was filled in the current collector obtained in the step (a) and dried at 100 ° C. for 30 minutes.
- An electrode was produced by compressing the dried product in the thickness direction using a pair of rolls.
- Two electrodes obtained in the above (1) were cut into a size of 1.5 cm ⁇ 1.5 cm, respectively, and used as a positive electrode and a negative electrode.
- Aluminum leads were welded to one surface of each of the positive electrode and the negative electrode.
- a cell separator made of an aluminum laminate sheet is formed by laminating a positive electrode and a negative electrode by interposing a cellulose separator (thickness: 60 ⁇ m) between the positive electrode and the negative electrode. Accommodated.
- EDLC (A1) was produced.
- the design capacity of EDLC (A1) was about 2.2 mAh / cm 2 at 3.3 V charge.
- Comparative Example 1 An electrode mixture slurry was prepared in the same manner as in Example 1 except that the alkali activated carbon used as the raw material of the active material in Example 1 was used as it was as the active material.
- EDLC (B1) was assembled and evaluated in the same manner as in Example 1 except that the obtained electrode mixture slurry was used. In addition, it was 7 micromol / g when the removal
- Example 2 The same electrode mixture slurry as used in Example 1 was applied to one surface of an aluminum foil (thickness 20 ⁇ m) as a current collector, and dried at 100 ° C. for 30 minutes. An electrode was produced by compressing the dried product in the thickness direction using a pair of rolls. Two electrodes thus produced were cut into a size of 1.5 cm ⁇ 1.5 cm to form a positive electrode and a negative electrode. An aluminum lead was welded to the other surface of each of the positive electrode and the negative electrode. An EDLC (A2) was produced in the same manner as in (2) of Example 1 except that the obtained positive electrode and negative electrode were used and laminated with one surface of the positive electrode and the negative electrode facing each other. The design capacity of EDLC (A2) was about 0.4 mAh / cm 2 when 3.3 V was charged. Table 1 shows the results of the evaluation (3) of Example 1 for the EDLCs of Examples 1 and 2 and Comparative Example 1.
- Example 3 (1) Production of negative electrode (a) Production of negative electrode current collector The surface area of the same thermosetting polyurethane foam used in (1) (a) of Example 1 was 5 g / cm 2 by sputtering. Cu film (conductive layer) was formed. A Cu layer was formed on the surface of the foam by applying a DC current having a cathode current density of 2 A / dm 2 by immersing it in a copper sulfate plating bath using a foam having a conductive layer formed on the surface as a workpiece. .
- the copper sulfate plating bath contained 250 g / L copper sulfate, 50 g / L sulfuric acid, and 30 g / L copper chloride, and the temperature was 30 ° C.
- the foam with the Cu layer formed on the surface was heat-treated at 700 ° C. in an air atmosphere to decompose the foam.
- a porous body made of copper (a negative electrode current collector) was obtained by reducing the oxide film formed on the surface by firing in a hydrogen atmosphere.
- the obtained negative electrode current collector had a three-dimensional network-like porous structure in which pores communicated, reflecting the pore shape of the foam, had a porosity of 92% by volume, and an average pore diameter of 550 ⁇ m.
- the BET specific surface area was 200 cm 2 / g.
- the three-dimensional network copper skeleton had a communication hole-like cavity formed by removing the foam.
- Step (2) Production of negative electrode A negative electrode mixture slurry was prepared by mixing artificial graphite powder as a negative electrode active material, acetylene black as a conductive additive, PVDF as a binder, and NMP as a dispersion medium. .
- the mass ratio of the graphite powder, acetylene black, and PVDF was 100: 5: 5.
- the obtained negative electrode mixture slurry was filled in the current collector obtained in the step (a) and dried at 100 ° C. for 30 minutes. The dried product was rolled using a pair of rolls to produce a negative electrode having a thickness of 210 ⁇ m.
- Step (1) the filling amount of the negative electrode mixture was adjusted so that the chargeable capacity of the negative electrode after pre-doping with lithium was about twice the capacity of the positive electrode.
- a lithium foil (thickness: 50 ⁇ m) is pressure-bonded to one surface of a punching copper foil (thickness: 20 ⁇ m, opening diameter: 50 ⁇ m, opening ratio 50%, 2 cm ⁇ 2 cm) as a current collector.
- a lithium electrode was produced.
- a nickel lead was welded to the other surface of the current collector of the lithium electrode.
- Single cell electrode by laminating the positive electrode and the negative electrode with a cellulose separator (thickness: 60 ⁇ m) interposed between the positive electrode and the negative electrode with the other surfaces of the positive electrode and the negative electrode facing each other Groups were formed. Further, a lithium separator is disposed on the negative electrode side of the electrode group with a polyolefin separator (a laminate of a polyethylene microporous membrane and a polypropylene microporous membrane), and the obtained laminate is made of an aluminum laminate sheet. It accommodated in the produced cell case.
- an electrolyte was injected into the cell case, and the positive electrode, the negative electrode, and the separator were impregnated.
- a solution in which LiPF 6 as a lithium salt was dissolved to a concentration of 1.0 mol / L in a mixed solvent containing ethylene carbonate and diethyl carbonate at a volume ratio of 1: 1 was used.
- the cell case was sealed while reducing the pressure with a vacuum sealer.
- the negative electrode lead wire and the lithium electrode lead wire were connected to a power source outside the cell case.
- the cell in this state was allowed to stand for a predetermined time in a thermostat at 30 ° C. so that the temperature of the electrolyte was the same as the temperature of the thermostat.
- the lithium metal was charged to a potential of 0 V, and then discharged with a current of 1.5 mA / cm 2 , 3.0 mAh,
- the negative electrode active material was predoped with lithium.
- the cell After pre-doping, the cell, in the current 1.5 mA / cm 2, and charged to the upper limit voltage 4.2 V at a current 1.5 mA / cm 2, the charge-discharge cycle for discharging until the voltage becomes 2.2V 20 Breaking-in and charging were performed by repeating the process. Then, one end of the sealed cell case was opened, and the gas generated in the cell was discharged out of the cell. After gas discharge, the opening was sealed again. In this way, a lithium ion capacitor (A3) was produced. The design capacity of the lithium ion capacitor (A3) was about 1.5 mAh / cm 2 when charged with 4.5V.
- Comparative Example 2 A lithium ion capacitor (B2) was produced and evaluated in the same manner as in Example 3 except that the same electrode as in Comparative Example 1 was used as the positive electrode.
- Example 4 The same thing as the negative mix slurry used in Example 3 was apply
- a lithium ion capacitor (A4) was produced in the same manner as in (3) of Example 3 except that the negative electrode thus obtained and the same positive electrode as that used in Example 2 were used as the positive electrode.
- the design capacity of the lithium ion capacitor (A4) was about 0.24 mAh / cm 2 when charged with 4.5V.
- Table 2 shows the results of the evaluation (4) of Example 3 for the lithium ion capacitors of Examples 3 to 4 and Comparative Example 2.
- the capacitor according to an embodiment of the present invention can obtain excellent cycle characteristics even though the upper limit voltage of charge / discharge is high. Therefore, it can be applied to various uses that require high capacity and high cycle characteristics.
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Abstract
Description
最初に、本発明の実施形態の内容を列記して説明する。
本発明の第1実施形態は、(1)正極と、負極と、前記正極および前記負極の間に介在するセパレータと、電解質とを含むキャパシタであって、前記キャパシタは、リチウムイオンキャパシタであり、前記正極は、正極集電体と、前記正極集電体に担持された正極活物質とを含み、前記正極活物質は、活性炭を含み、前記活性炭は、カルボキシル基を有し、かつ300℃から500℃まで昇温加熱したときの前記活性炭の単位質量当たりのカルボキシル基の脱離量が0.03μmol/g以下であり、4.2V以上の充放電の上限電圧を有する、キャパシタに関する。
第3実施形態によれば、活性炭に含まれるカルボキシル基による電解質の分解が抑制されるため、4.2V以上の上限電圧でもリチウムイオンキャパシタの充放電を繰り返し行うことができ、サイクル特性の低下を抑制できる。
第4実施形態によれば、活性炭に含まれるカルボキシル基による電解質の分解が抑制されるため、3.3V以上の上限電圧でもEDLCの充放電を繰り返し行うことができ、サイクル特性の低下を抑制できる。
本発明の実施形態に係るキャパシタの具体例を、適宜図面を参照しつつ以下に説明する。なお、本発明はこれらの例示に限定されるものではなく、請求の範囲によって示され、請求の範囲と均等の意味および範囲内での全ての変更が含まれることが意図される。
本発明の実施形態に係るキャパシタには、リチウムイオンキャパシタおよびEDLCが含まれる。いずれのキャパシタも、正極と、負極と、正極および負極の間に介在するセパレータと、電解質とを含む。
(正極)
正極は、正極集電体と、正極集電体に担持された正極活物質とを含む。正極は、正極活物質を含む正極合剤と、正極合剤が担持された正極集電体とを含んでもよい。正極は、リチウムイオンキャパシタとEDLCとで共通のものが使用できる。
負極は、負極活物質を含む。負極は、負極活物質と、負極活物質が担持された負極集電体とを含むことができる。負極集電体の材質としては、銅、銅合金、ニッケル、ニッケル合金、ステンレス鋼、アルミニウム、および/またはアルミニウム合金などが好ましい。負極集電体としては、金属箔を用いてもよく、蓄電デバイスを高容量化する観点から、金属多孔体を用いてもよい。
セパレータは、イオン透過性を有し、正極と負極との間に介在して、これらを物理的に離間させて短絡を防止する。セパレータは、多孔質構造を有し、細孔内に電解質を保持することで、イオンを透過させる。セパレータの材質としては、例えば、ポリエチレン、および/またはポリプロピレンなどのポリオレフィン;ポリエチレンテレフタレートなどのポリエステル;ポリアミド;ポリイミド;セルロース;および/またはガラス繊維などを用いることができる。
電解質はカチオンおよびアニオンを含む。電解質としては、非水電解質が好ましく使用される。各キャパシタの電解質について以下に説明する。
(リチウムイオンキャパシタの電解質)
リチウムイオンキャパシタの電解質は、リチウムイオン伝導性を有する。このような電解質では、カチオンは、少なくともリチウムイオンを含む。非水電解質としては、例えば、非水溶媒(または有機溶媒)にリチウムイオンとアニオンとの塩(リチウム塩)を溶解させた電解質(有機電解質)、および少なくともリチウムイオンを含むカチオンとアニオンとを含むイオン液体などが用いられる。
EDLCに使用される電解質は、非水電解質であることが好ましい。電解質としては、カチオン(第3カチオン)とアニオン(第3アニオン)との塩を非水溶媒(または有機溶媒)に溶解させた電解質、ならびにカチオン(第4カチオン)およびアニオン(第4アニオン)を含むイオン液体などの非水電解質が好ましく用いられる。
以上の実施形態に関し、さらに以下の付記を開示する。
(付記1)
正極と、負極と、前記正極および前記負極の間に介在するセパレータと、電解質とを含むキャパシタであって、前記キャパシタは、リチウムイオンキャパシタであり、前記正極は、正極集電体と、前記正極集電体に担持された正極活物質とを含み、前記正極活物質は、活性炭を含み、前記活性炭は、カルボキシル基を有し、かつ300℃から500℃まで昇温加熱したときの前記活性炭の単位質量当たりのカルボキシル基の脱離量が0.03μmol/g以下であり、4.2V以上の充放電の上限電圧を有する、キャパシタ。
正極と、負極と、前記正極および前記負極の間に介在するセパレータと、電解質とを含むキャパシタであって、前記キャパシタは、EDLCであり、前記正極は、正極集電体と、前記正極集電体に担持された正極活物質とを含み、前記正極活物質は、活性炭を含み、前記活性炭は、カルボキシル基を有し、かつ300℃から500℃まで昇温加熱したときの前記活性炭の単位質量当たりのカルボキシル基の脱離量が0.03μmol/g以下であり、3.3V以上の充放電の上限電圧を有する、キャパシタ。
付記1および付記2のキャパシタによれば、充放電の上限電圧を、リチウムイオンキャパシタで4.2V以上に、EDLCで3.3V以上に高めても、カルボキシル基が関与する電解質の分解反応を抑制でき、これにより、サイクル特性に優れるキャパシタが得られる。
付記1または付記2のキャパシタにおいて、前記正極集電体は、三次元網目状の骨格を有し、前記正極の厚みは、500~2000μmであり、前記活性炭の比表面積は、1600~3200m2/gであり、前記活性炭はアルカリを含み、前記活性炭中の前記アルカリの含有量は、20~500ppmであることが好ましい。
このようなキャパシタでは、内部抵抗の増加が抑制され、サイクル特性をさらに高めることができる。また、高容量化および/または高出力化の観点からも有利である。
上記付記1または付記2のキャパシタと、前記キャパシタの充電を制御する充電制御ユニットと、前記キャパシタの放電を制御する放電制御ユニットとを含む充放電システム。
このような充放電システムでは、キャパシタの充放電の上限電圧を、リチウムイオンキャパシタで4.2V以上に、EDLCで3.3V以上に、それぞれ高めても、カルボキシル基が関与する電解質の分解反応を抑制でき、これにより、キャパシタのサイクル特性を向上できる。
下記の手順でEDLCを作製した。
(1)電極の作製
(a)集電体の作製
熱硬化性ポリウレタンの発泡体(気孔率:95体積%、表面1インチ(=2.54cm)長さ当たりの空孔(セル)数:約50個、縦100mm×横30mm×厚み1.1mm)を準備した。発泡体を、黒鉛、カーボンブラック(平均粒径D50:0.5μm)、樹脂バインダ、浸透剤、および消泡剤を含む導電性懸濁液の中に浸漬した後、乾燥することにより、発泡体の表面に導電性層を形成した。なお、懸濁液中の黒鉛およびカーボンブラックの含有量は合計で25質量%であった。
(b-1)活物質の調製
5体積%の水素ガスと95体積%のアルゴンとを含む還元性ガス雰囲気下(圧力:約0.1MPa)で、市販のアルカリ賦活炭(比表面積2300m2/g、平均粒径約5μm)を加熱することにより還元した。加熱は、室温から700℃まで1時間かけて昇温し、次いで、700℃で1時間かけて行った。得られた還元物は、活物質として用いた。なお、還元物(活性炭)は、加熱後、室温まで冷却し、冷却したものを、活物質として電極合剤スラリーの調製に供した。
上記(b-1)で得られた活物質、導電助剤としてのアセチレンブラック、およびPVDF(バインダ)のNMP溶液(PVDF濃度:2.3質量%)を、混合機を用いて、撹拌下で混合することにより、電極合剤スラリー調製した。活物質と、アセチレンブラックと、PVDFとの質量比は、100:10.7:5.7とした。得られた電極合剤スラリーを、上記工程(a)で得られた集電体に充填し、100℃にて30分乾燥した。乾燥物を、一対のロールを用いて厚み方向に圧縮することにより、電極を作製した。
上記(1)で得られた電極を、それぞれ、1.5cm×1.5cmのサイズに2枚切り出し、正極および負極とした。正極および負極のそれぞれの一方の表面にアルミニウム製のリードを溶接した。正極と負極との間に、セルロース製のセパレータ(厚み:60μm)を介在させて正極と負極とを積層することにより単セルの電極群を形成し、アルミニウムラミネートシートで作製されたセルケース内に収容した。
得られたEDLCを用いて、下記の評価を行った。
(a)サイクル特性
EDLCを、20mA/cm2の電流で、上限電圧Vuまで充電し、20mA/cm2の電流で、電圧が0.1Vになるまで放電した。このときの放電容量(初期容量)を求めた。上記の充電および放電のサイクルを、合計5000回繰り返し、5000回目の放電容量を求め、初期容量を100%としたときの比率(%)を算出した。サイクル特性は、上限電圧Vuが3.3Vおよび2.5Vのそれぞれの場合について評価した。
(b)内部抵抗
上記(a)でサイクル特性を評価した後のEDLCの内部抵抗を、交流電流の周波数1kHzで、交流インピーダンス法により測定した。
実施例1で活物質の原料として用いたアルカリ賦活炭を、そのまま活物質として用いる以外は、実施例1と同様にして、電極合剤スラリーを調製した。得られた電極合剤スラリーを用いる以外は、実施例1と同様にして、EDLC(B1)を組み立て、評価を行った。なお、アルカリ賦活炭のカルボキシル基の脱離量を、実施例1と同様にして求めたところ、7μmol/gであった。
実施例1で用いた電極合剤スラリーと同じものを、集電体としてのアルミニウム箔(厚み20μm)の一方の表面に塗布し、100℃にて30分乾燥した。乾燥物を、一対のロールを用いて厚み方向に圧縮することにより、電極を作製した。このようにして作製した電極を、1.5cm×1.5cmのサイズに2枚切り出し、正極および負極とした。正極および負極のそれぞれの他方の表面に、アルミニウム製のリードを溶接した。得られた正極および負極を用い、正極および負極の一方の表面同士を対向させた状態で積層する以外は、実施例1の(2)と同様にして、EDLC(A2)を作製した。EDLC(A2)の設計容量は、3.3V充電時で約0.4mAh/cm2であった。実施例1~2および比較例1のEDLCについて、実施例1の上記(3)の評価を行った結果を表1に示す。
(1)負極の作製
(a)負極集電体の作製
実施例1の(1)(a)で用いたものと同じ熱硬化性ポリウレタンの発泡体の表面に、スパッタリングにより目付量5g/cm2のCu被膜(導電性層)を形成した。表面に導電性層を形成した発泡体をワークとして、硫酸銅メッキ浴中に浸漬して、陰極電流密度2A/dm2の直流電流を印加することにより、発泡体の表面にCu層を形成した。硫酸銅メッキ浴は、250g/Lの硫酸銅、50g/Lの硫酸、および30g/Lの塩化銅を含み、温度は、30℃であった。
負極活物質としての人造黒鉛粉末と、導電助剤としてのアセチレンブラックと、バインダとしてのPVDFと、分散媒としてのNMPとを混合することにより、負極合剤スラリーを調製した。黒鉛粉末と、アセチレンブラックと、PVDFとの質量比は、100:5:5であった。得られた負極合剤スラリーを、上記工程(a)で得られた集電体に充填し、100℃にて30分乾燥した。乾燥物を、一対のロールを用いて圧延し、厚み210μmの負極を作製した。なお、工程(1)では、リチウムをプレドープした後の負極の充電可能な容量が、正極の容量の約2倍となるように、負極合剤の充填量を調節した。
集電体としてのパンチング銅箔(厚み:20μm、開口径:50μm、開口率50%、2cm×2cm)の一方の表面に、リチウム箔(厚み:50μm)を圧着することにより、リチウム極を作製した。リチウム極の集電体の他方の表面には、ニッケル製のリードを溶接した。
実施例1で作製したものと同じ電極を正極として用いた。この正極および上記(1)で得られた負極を、それぞれ、1.5cm×1.5cmのサイズに切り出した。正極の一方の表面には、アルミニウム製のリードを、負極の一方の表面には、ニッケル製のリードを、それぞれ溶接した。
得られたリチウムイオンキャパシタを用い、上限電圧Vuを、4.2V、4.5Vまたは3.8Vに変更する以外は、実施例1の(3)評価と同様にして、サイクル特性および内部抵抗を評価した。
(a)サイクル特性
リチウムイオンキャパシタを、5mA/cm2の電流で、上限電圧Vuまで充電し、5mA/cm2の電流で、電圧が2.3Vになるまで放電した。このときの放電容量(初期容量)を求めた。上記の充電および放電のサイクルを、合計2000回繰り返し、2000回目の放電容量を求め、初期容量を100%としたときの比率(%)を算出した。サイクル特性は、上限電圧Vuが4.5V、4.2Vおよび3.8Vのそれぞれの場合について評価した。
(b)内部抵抗
上記(a)でサイクル特性を評価した後のリチウムイオンキャパシタの内部抵抗を、交流電流の周波数1kHzで、交流インピーダンス法により測定した。
比較例1と同じ電極を正極として用いる以外は、実施例3と同様にして、リチウムイオンキャパシタ(B2)を作製し、評価を行った。
実施例3で用いた負極合剤スラリーと同じものを、銅箔(厚み15μm)の一方の表面に塗布し、100℃にて30分乾燥した。乾燥物を、一対のロールを用いて厚み方向に圧縮することにより、負極を作製した。このようにして作製した負極を、1.5cm×1.5cmのサイズに切り出し、他方の表面に、ニッケル製のリードを溶接し、負極として用いた。
実施例3~4および比較例2のリチウムイオンキャパシタについて、実施例3の上記(4)の評価を行った結果を表2に示す。
Claims (8)
- 正極と、負極と、前記正極および前記負極の間に介在するセパレータと、電解質とを含むキャパシタであって、
前記キャパシタは、リチウムイオンキャパシタであり、
前記正極は、正極集電体と、前記正極集電体に担持された正極活物質とを含み、
前記正極活物質は、活性炭を含み、
前記活性炭は、カルボキシル基を有し、かつ300℃から500℃まで昇温加熱したときの前記活性炭の単位質量当たりのカルボキシル基の脱離量が0.03μmol/g以下であり、
4.2V以上の充放電の上限電圧を有する、キャパシタ。 - 正極と、負極と、前記正極および前記負極の間に介在するセパレータと、電解質とを含むキャパシタであって、
前記キャパシタは、電気二重層キャパシタであり、
前記正極は、正極集電体と、前記正極集電体に担持された正極活物質とを含み、
前記正極活物質は、活性炭を含み、
前記活性炭は、カルボキシル基を有し、かつ300℃から500℃まで昇温加熱したときの前記活性炭の単位質量当たりのカルボキシル基の脱離量が0.03μmol/g以下であり、
3.3V以上の充放電の上限電圧を有する、キャパシタ。 - 前記正極集電体は、三次元網目状の骨格を有する請求項1または請求項2に記載のキャパシタ。
- 前記正極の厚みは、500~2000μmである請求項3に記載のキャパシタ。
- 前記活性炭の比表面積は、1200~3500m2/gである請求項1~請求項4のいずれか1項に記載のキャパシタ。
- 前記上限電圧は4.5V以上である請求項1に記載のキャパシタ。
- キャパシタの充放電方法であって、
前記キャパシタは、リチウムイオンキャパシタであり、
前記正極は、正極集電体と、前記正極集電体に担持された正極活物質とを含み、
前記正極活物質は、活性炭を含み、
前記活性炭は、カルボキシル基を有し、かつ300℃から500℃まで昇温加熱したときの前記活性炭の単位質量当たりのカルボキシル基の脱離量が0.03μmol/g以下であり、
前記キャパシタを、4.2V以上の上限電圧で、充放電する工程を含む充放電方法。 - キャパシタの充放電方法であって、
前記キャパシタは、電気二重層キャパシタであり、
前記正極は、正極集電体と、前記正極集電体に担持された正極活物質とを含み、
前記正極活物質は、活性炭を含み、
前記活性炭は、カルボキシル基を有し、かつ300℃から500℃まで昇温加熱したときの前記活性炭の単位質量当たりのカルボキシル基の脱離量が0.03μmol/g以下であり、
前記キャパシタを、3.3V以上の上限電圧で、充放電する工程を含む充放電方法。
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- 2015-02-02 WO PCT/JP2015/052812 patent/WO2015125594A1/ja active Application Filing
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Publication number | Publication date |
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CN106030741A (zh) | 2016-10-12 |
JP2015154039A (ja) | 2015-08-24 |
EP3109877A4 (en) | 2017-03-29 |
EP3109877A1 (en) | 2016-12-28 |
KR20160124084A (ko) | 2016-10-26 |
US20170011860A1 (en) | 2017-01-12 |
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